Originally Posted by
chevvron
Not since it was 'stolen' by DRA/DERA/Qinetiq and moved to Cody Site about a mile to the northwest.
3.5 deg GPs were adopted due to a design system called 'APATC-1' which was mandated for MOD airfields back in the '80s.
This involved a different way of calculating approach minima compared to the ICAO method used for civil airfelds, the 'dominant obsatcle' on runway 24 being --- the control tower!!
Once that was demolished in early 2003, we could have reduced to a 3 deg GP under both APATC-1 and ICAO methods of iap design.
Yes, I do remember “Apache one”. In the 1980s I was based at the military airfield about seven miles to the south west.
Its introduction resulted in a rethink and a lot of discussion about how we calculated our approach minima. The “En Route Supplement” contained a few anomalies, especially as the RAF flew instrument approaches on QFE. I remember ringing ATC at an airfield not far away to try to ascertain if the minima published in the “Red book” was calculated on QFE or QNH, because there was only a single figure stated, rather than the two quoted for other airfields. We were rather astonished to hear that the ATCO didn’t know!